Ostomy pouches are known in a series of different shapes and sizes adapted according to their purpose. However, it is a common feature that they ordinarily consist of two pouch walls welded together along their contour. One of the walls has an aperture which receives material discharged from the stoma. An adhesive label or faceplate is affixed to the pouch wall around the stomal aperture by welding or adhesion. The adhesive label permits the detachable fastening of the pouch on the user's body around stoma.
In the production of such ostomy pouches, the starting material used is generally two webs of weldable plastic sheet material that are advanced stepwise through an apparatus with three stations. The first station has a punching tool to produce the apertures in one of the webs, the adhesive label being welded onto said web around the apertures at the second station, and the two webs being subsequently brought together and united along a line corresponding to the wanted contour of the pouch by means of an annular welding electrode at the third station. The finished pouches may simultaneously be separated from the remaining sheet material.
As the contour welding operation cannot be carried out through the adhesive label it is a primary condition in this technique of production that the label be positioned entirely within the contour of the pouch. In many cases, this is completely acceptable. However, in other cases, it means that for production reasons the pouch must be made bigger than otherwise necessary or that the distance from the aperture to the top of the pouch must be lengthened. The use of a pouch having such increased dimensions can result in the upper part of the pouch pulling outwardly from the user's body as a consequence of the increase in weight when the pouch fills.